Page Types Within a Table Extent

Within the extent, individual pages contain different types of data. Extent pages for a table can be separated into the following categories:
  • Data pages

    Data pages contain the data rows for the table.

  • Bitmap pages

    Bitmap pages contain control information that monitors the fullness of every page in the extent.

  • Blobpages

    Blobpages contain TEXT and BYTE data that is stored with the data rows in the dbspace. TEXT and BYTE data that resides in a blobspace is stored in blobpages, a structure that is completely different than the structure of a dbspace blobpage.

  • Free pages

    Free pages are pages in the extent that are allocated for tblspace use, but whose function has not yet been defined. Free pages can be used to store any kind of information: data, including TEXT or BYTE data types; index; or bitmap.

Figure 1 illustrates the possible structure of a nonfragmented table with an initial-extent size of 8 pages and a next-extent size of 16 pages.
Figure 1. Extent Structure of a Table
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